Chamber throats in LCR cylinder?

I just purchased a new .327 LCR and was measuring the chamber throats. I first noticed that with all but one chamber I could drop my XTP bullets straight thru. So I measured the throats and got .3105”, .3140”, .3125”, .3130”, .3115”, .3140”. Those numbers aren’t anything I would think are acceptable for chamber throats.

Does this need to go back to Ruger or is it acceptable for a snubby?

Dave DeLaurant said:

Those numbers wouldn't make me happy, but before making any decisions I'd personally shoot it a bit and see what practical difference these variations make at snub nose distances.

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It's obviously a QC problem/failure. I think Ruger needs to fix it!

I've always thought the throat diameter should narrow down to ~.001 less that the grove diameter? So for a 32 cal round with an canonical grove diameter of .312 the throat diameter should be .311.

If that's not true, what should the ideal throat diameter be?

TTv2 said:

From what I've seen, Ruger holds the throats on their .327's big at .314 because they're clearly intending for them to be shot with jacketed bullets and want to keep pressure low. Shoving a .312 jacketed bullet thru a .311 throat at 45k PSI screams kaboom.

Besides that, the throats on every chamber should measure the same.

Send it back.

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If they are afraid a KABOOM!, why not simply make the throat diameter .312", the bullet's canonical diameter ?

I went to the SAAMI spec and looked at the 32 H&R and 327 Mag specs and the canonical throat diameter is .314”

The chamber spec is the bottom diagram: .314".